(i) Technical Field
The present invention relates to radio clocks.
(ii) Related Art
A radio clock receives satellite signals transmitted from GPS (Global Positioning System) satellites, and corrects the time of the internal clock based on the time information contained in the received satellite signals. By doing so, the radio clock displays highly-accurate time. However, the power consumption by the reception module that extracts time information and the like from satellite signals received from GPS satellites is large. Therefore, the issue is how long the life of a battery-driven radio clock can be maintained. Japanese Unexamined Patent Application Publication Nos. 2011-226813, 2011-226933, and 10-82875 disclose radio clocks that consume less power and have longer operating times.
However, Japanese Unexamined Patent Application Publication Nos. 2011-226813, 2011-226933, and 10-82875 do not disclose a technique for optimizing the frequency of satellite signal reception and the duration of a receiving process in accordance with the environment to receive satellite signals.